Support assigning material sets as usages from UI #5933

It's on alt+click in Materials UI, see example - https://imgur.com/a/8gP7iAZ

src/bonsai/bonsai/bim/module/material/operator.py

@@ -29,7 +29,7 @@ import bonsai.core.style
 import bonsai.core.material as core
 import bonsai.bim.module.model.profile as model_profile
 from bonsai.bim.ifc import IfcStore
-from typing import Any, Union
+from typing import Any, Union, TYPE_CHECKING
 
 
 class LoadMaterials(bpy.types.Operator):
@@ -202,9 +202,17 @@ class RemoveMaterialSet(bpy.types.Operator, tool.Ifc.Operator):
 class AssignMaterialToSelected(bpy.types.Operator, tool.Ifc.Operator):
     bl_idname = "bim.assign_material_to_selected"
     bl_label = "Assign Material To Selected"
-    bl_description = "Assign currently selected material in Materials UI to the selected objects"
+    bl_description = (
+        "Assign currently selected material in Materials UI to the selected objects.\n\n"
+        "ALT+CLICK to assign material as a usage."
+    )
     bl_options = {"REGISTER", "UNDO"}
     material: bpy.props.IntProperty(name="Material IFC ID")
+    assign_as_usage: bpy.props.BoolProperty(
+        name="Assign Material As A Usage",
+        default=False,
+        options={"SKIP_SAVE"},
+    )
 
     @classmethod
     def poll(cls, context):
@@ -213,13 +221,25 @@ class AssignMaterialToSelected(bpy.types.Operator, tool.Ifc.Operator):
             return False
         return True
 
+    def invoke(self, context, event):
+        if event.type == "LEFTMOUSE" and event.alt:
+            material_class = tool.Ifc.get().by_id(self.material).is_a()
+            if material_class not in ("IfcMaterialProfileSet", "IfcMaterialLayerSet"):
+                self.report({"ERROR"}, f"{material_class} cannot be assigned as a usage.")
+                return {"CANCELLED"}
+            self.assign_as_usage = True
+        return self.execute(context)
+
     def _execute(self, context):
         material = tool.Ifc.get().by_id(self.material)
         objects = tool.Blender.get_selected_objects()
+        material_type = material.is_a()
+        if self.assign_as_usage:
+            material_type += "Usage"
         core.assign_material(
             tool.Ifc,
             tool.Material,
-            material_type=tool.Material.get_active_material_type(),
+            material_type=material_type,
             objects=objects,
             material=material,
         )

src/ifcopenshell-python/ifcopenshell/api/material/assign_material.py

@@ -22,7 +22,8 @@ import ifcopenshell.api.material
 import ifcopenshell.guid
 import ifcopenshell.util.element
 import ifcopenshell.util.representation
-from typing import Optional, Union
+from collections import defaultdict
+from typing import Optional, Union, Any
 
 
 def assign_material(
@@ -156,6 +157,9 @@ def assign_material(
 
 
 class Usecase:
+    file: ifcopenshell.file
+    settings: dict[str, Any]
+
     def execute(self):
         self.products: set[ifcopenshell.entity_instance] = set(self.settings["products"])
         if not self.products:
@@ -167,7 +171,9 @@ class Usecase:
             ifcopenshell.api.material.unassign_material(self.file, products=products_to_unassign_material)
 
         if self.settings["type"] == "IfcMaterial" or (
-            self.settings["material"] and not self.settings["material"].is_a("IfcMaterial")
+            self.settings["material"]
+            and not self.settings["material"].is_a("IfcMaterial")
+            and not self.settings["type"].endswith("Usage")
         ):
             return self.assign_ifc_material()
 
@@ -180,11 +186,6 @@ class Usecase:
             return self.create_material_association(material_set)
 
         elif self.settings["type"] == "IfcMaterialLayerSetUsage":
-            # NOTE: might return list of rels
-            types_to_products_layers_sets: dict[
-                tuple[Union[ifcopenshell.entity_instance, None], str], tuple[ifcopenshell.entity_instance, list]
-            ] = dict()
-
             AXIS3_CLASSES = [
                 "IfcSlab",
                 "IfcSlabStandardCase",
@@ -196,28 +197,47 @@ class Usecase:
                 "IfcCovering",
                 "IfcFurniture",
             ]
+
+            provided_material_set = None
+            if self.settings["material"]:
+                provided_material_set = self.settings["material"]
+                material_set_class = provided_material_set.is_a()
+                assert (
+                    material_set_class == "IfcMaterialLayerSet"
+                ), f"{material_set_class} cannot be assiged as a IfcMaterialLayerSetUsage."
+
+            layer_types_to_products: defaultdict[
+                tuple[ifcopenshell.entity_instance, str], list[ifcopenshell.entity_instance]
+            ]
+            layer_types_to_products = defaultdict(list)
+            types_to_material_sets: dict[Union[ifcopenshell.entity_instance, None], ifcopenshell.entity_instance]
+            types_to_material_sets = {}
+
             for product in self.products:
-                element_type = ifcopenshell.util.element.get_type(product)
-                layer_set_direction = "AXIS3" if product.is_a() in AXIS3_CLASSES else "AXIS2"
-                material_layer_type = (element_type, layer_set_direction)
-
-                if material_layer_type in types_to_products_layers_sets:
-                    types_to_products_layers_sets[material_layer_type][1].append(product)
-                    continue
-
-                if element_type:
-                    element_type_material = ifcopenshell.util.element.get_material(element_type)
-                    if element_type_material and element_type_material.is_a("IfcMaterialLayerSet"):
-                        material_set = element_type_material
-                    else:
-                        material_set = self.file.create_entity("IfcMaterialLayerSet")
+                # Figure what material set to assign.
+                if provided_material_set is not None:
+                    material_set = provided_material_set
                 else:
-                    material_set = self.file.create_entity("IfcMaterialLayerSet")
-                types_to_products_layers_sets[material_layer_type] = (material_set, [product])
+                    # If material set is not provided, derive it from the type.
+                    element_type = ifcopenshell.util.element.get_type(product)
+                    if element_type in types_to_material_sets:
+                        material_set = types_to_material_sets[element_type]
+                    else:
+                        element_type_material = None
+                        if element_type is not None:
+                            element_type_material = ifcopenshell.util.element.get_material(element_type)
+                        if element_type_material and element_type_material.is_a("IfcMaterialLayerSet"):
+                            material_set = element_type_material
+                        else:
+                            material_set = self.file.create_entity("IfcMaterialLayerSet")
+
+                layer_set_direction = "AXIS3" if product.is_a() in AXIS3_CLASSES else "AXIS2"
+                material_layer_type = (material_set, layer_set_direction)
+                layer_types_to_products[material_layer_type].append(product)
 
             rels = [
                 self.create_layer_set_usage(material_set, layer_set_direction, products)
-                for (_, layer_set_direction), (material_set, products) in types_to_products_layers_sets.items()
+                for (material_set, layer_set_direction), products in layer_types_to_products.items()
             ]
             return rels[0] if len(rels) == 1 else rels
 
@@ -226,27 +246,41 @@ class Usecase:
             return self.create_material_association(material_set)
 
         elif self.settings["type"] == "IfcMaterialProfileSetUsage":
-            # NOTE: might return list of rels
-            types_to_products_profile_sets: dict[
-                Union[ifcopenshell.entity_instance, None], tuple[ifcopenshell.entity_instance, list]
-            ] = dict()
-            for product in self.products:
-                element_type = ifcopenshell.util.element.get_type(product)
-                if element_type in types_to_products_profile_sets:
-                    types_to_products_profile_sets[element_type][1].append(product)
-                    continue
-                if element_type:
-                    element_type_material = ifcopenshell.util.element.get_material(element_type)
-                    if element_type_material and element_type_material.is_a("IfcMaterialProfileSet"):
-                        material_set = element_type_material
-                    else:
-                        material_set = self.file.create_entity("IfcMaterialProfileSet")
-                else:
-                    material_set = self.file.create_entity("IfcMaterialProfileSet")
-                types_to_products_profile_sets[element_type] = (material_set, [product])
+            provided_material_set = None
+            if self.settings["material"]:
+                provided_material_set = self.settings["material"]
+                material_set_class = provided_material_set.is_a()
+                assert (
+                    material_set_class == "IfcMaterialProfileSet"
+                ), f"{material_set_class} cannot be assiged as a IfcMaterialProfileSetUsage."
 
-            rels = []
-            for _, (material_set, products) in types_to_products_profile_sets.items():
+            material_sets_to_products: dict[ifcopenshell.entity_instance, list[ifcopenshell.entity_instance]]
+            material_sets_to_products = defaultdict(list)
+            types_to_material_sets: dict[Union[ifcopenshell.entity_instance, None], ifcopenshell.entity_instance]
+            types_to_material_sets = {}
+
+            for product in self.products:
+                # Figure what material set to assign.
+                if provided_material_set is not None:
+                    material_set = provided_material_set
+                else:
+                    # If material set is not provided, derive it from the type.
+                    element_type = ifcopenshell.util.element.get_type(product)
+                    if element_type in types_to_material_sets:
+                        material_set = types_to_material_sets[element_type]
+                    else:
+                        element_type_material = None
+                        if element_type is not None:
+                            element_type_material = ifcopenshell.util.element.get_material(element_type)
+                        if element_type_material and element_type_material.is_a("IfcMaterialProfileSet"):
+                            material_set = element_type_material
+                        else:
+                            material_set = self.file.create_entity("IfcMaterialProfileSet")
+
+                material_sets_to_products[material_set].append(product)
+
+            rels: list[ifcopenshell.entity_instance] = []
+            for material_set, products in material_sets_to_products.items():
                 self.update_representation_profile(material_set, products)
                 material_set_usage = self.create_profile_set_usage(material_set)
                 rels.append(self.create_material_association(material_set_usage, products))
@@ -286,7 +320,7 @@ class Usecase:
                 "LayerSetDirection": layer_set_direction,
                 "DirectionSense": "POSITIVE",
                 "OffsetFromReferenceLine": 0,
-            }
+            },
         )
         return self.create_material_association(usage, products)
 
@@ -317,7 +351,7 @@ class Usecase:
                 "OwnerHistory": ifcopenshell.api.owner.create_owner_history(self.file),
                 "RelatedObjects": products,
                 "RelatingMaterial": relating_material,
-            }
+            },
         )
 
     def get_rel_associates_material(

src/ifcopenshell-python/test/api/material/test_assign_material.py

@@ -139,6 +139,18 @@ class TestAssignMaterialIFC2X3(test.bootstrap.IFC2X3):
         assert material_list.Materials[0] == material
         assert ifcopenshell.util.element.get_material(element2) == material_list
 
+    def test_assign_element_material_layer_set_usage_with_provided_material_set(self):
+        element_type1 = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcWallType")
+        element1 = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcWall")
+        ifcopenshell.api.type.assign_type(self.file, related_objects=[element1], relating_type=element_type1)
+        ifcopenshell.api.material.assign_material(self.file, products=[element_type1], type="IfcMaterialLayerSet")
+
+        provided_material_set = self.file.create_entity("IfcMaterialLayerSet")
+        ifcopenshell.api.material.assign_material(
+            self.file, products=[element1], material=provided_material_set, type="IfcMaterialLayerSetUsage"
+        )
+        assert ifcopenshell.util.element.get_material(element1, should_skip_usage=True) == provided_material_set
+
 
 class TestAssignMaterialIFC4(test.bootstrap.IFC4, TestAssignMaterialIFC2X3):
     def test_assign_type_material_profile_set(self):
@@ -204,3 +216,15 @@ class TestAssignMaterialIFC4(test.bootstrap.IFC4, TestAssignMaterialIFC2X3):
         assert material_set.is_a("IfcMaterialConstituentSet")
         assert not material_set.MaterialConstituents
         assert ifcopenshell.util.element.get_material(element2) == material_set
+
+    def test_assign_element_material_profile_set_usage_with_provided_material_set(self):
+        element_type1 = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcWallType")
+        element1 = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcWall")
+        ifcopenshell.api.type.assign_type(self.file, related_objects=[element1], relating_type=element_type1)
+        ifcopenshell.api.material.assign_material(self.file, products=[element_type1], type="IfcMaterialProfileSet")
+
+        provided_material_set = self.file.create_entity("IfcMaterialProfileSet")
+        ifcopenshell.api.material.assign_material(
+            self.file, products=[element1], material=provided_material_set, type="IfcMaterialProfileSetUsage"
+        )
+        assert ifcopenshell.util.element.get_material(element1, should_skip_usage=True) == provided_material_set